Question: $\dfrac{4}{5} + \dfrac{9}{8} = {?}$
Answer: $ = {\dfrac{4 \times 8}{5 \times 8}} + {\dfrac{9 \times 5}{8 \times 5}} $ $ = {\dfrac{32}{40}} + {\dfrac{45}{40}} $ $ = \dfrac{{32} + {45}}{40} $ $ = \dfrac{77}{40}$